Telephone-exchange-system impulse-transmitter.



J. ERICKSOM TELEPHONE EXCHANGE SYSTEM IMPULSE TRANSMITTER.

APPLLUATION FILED JUNE 14, 1909 RENEWED MAY 13, 1912.

Patented Mar. 80, 1915.

2 SHEETS-SHEET 1.

Wafrz 855 635 4 JM'M/ JOHN ERICKSON, '3 CHICAGO, ILLINOIS, ASSIGNQFZ. TOAUTOMATIC- ELECTRIC SCLZEAIPL 9F CHICAGO, ILLINOIS, A COR-EORATICN SFILLINOIS.

TELEPHGNE-EXCHANGE-SYSTEM IMPULSE-TRANSMITTER.

Specification of Letters ratent.

Patented Mar, 3% 1M Application filed June 14, 1909, Serial No. 501,973.Renewed May 13, 1912. Serial. No. 897,079.

To all 'ur/aim. it 'i/MU/ 0071a. 22

Be it known that I, Join iliiicnsow, a 4

citizen of the United States of America, and resident or" Chicago, Cool:county, Illinois, have invented a certain new and useful improvement inTelephone-Exchauge-System Impulse-Transmitters, of which the followingis a specification.

My invention contemplates an electriral impulsetransniitter, such asthose used in automatic telephone exchange systems, comprisiug' a hackand forth rotary dial for operating the make-and-hreal; mechanism, andmeans for holding the dial locked in any position to which it advanced,together with means for releasing the malte-and-break mechanism by aslight backward movement of the dial, whereby the impulse wheel of themake-and-breal; mechanism rotates back to normal position while the dialremains locked in its advanced position, after which the dial. returnsto normal position. By thus holding the dial lockedwl1ile the impulsesare being transmitted the operation cannot be interfered with, as byundue acceleration. of the dial, and thus the proper transmission of theimpulses is insured, together with the desired operation of the switchesat the central station.

in impulse mechanism characterized by my invention is applicable to athree-wire system, and is also applicable to a two-wire system, beingespecially advantageous in the latter, because of-the importance in atwowire system of precluding interference with the transmission of theimpulses by the call ing subscriber.

In the accompanying drawings Figure. l is a rear elevation of animpulse-transmit ting mecaanism embodying the principles of myinvention. Fig. 2 is a vertical section on line L-- in Fig. 1. Fig. 3 isa VlGW similar to Fig/i, but showing certain portions of the structurebroken away to bring other oleine-nts into view. Fig at is a frontelevation of the said mechanism, with the dial removed and with certainother portions broken away, showing the mechanism in normalposition-that is to say, normal except for the removal of the receiverfrom the switch hook, which serves to unlock the dial. Fig. is a Viewsimilar to Fig. -l, showing the positions of certain elements when thedial is rotated or advanced from its normal position. Fig. 6 is a detailfrog- 1. At ts forward end said shaft is pro mentary perspective view ofthe malts-andbreak device. Figs. 7 and 8 are in the nature of diagramsillustrating the operation of the said makeaml-hrealt device.

As thus illustrated my invention com- 6 prises a frame A. of the usualor any suitable shape, which is rigidly connected with the frontplate a.The shaft B extends centrally through the said frame andfront plate, andis controlled at its rear end by a spring Z), which latter has its outerend secured to the frame at Z1, and .its inner end suitably secured tothe said shaft at 7%, in the manner shown more clearly in F videith ahub b that turns or rotates in the plate a, and which serves to rigidlycon-" nect the said shaft with the plate or wheel C. The dial D, whichis of the usual pattern or design, is pivoted uponfa frame (Z secured tothe front of the plate a, so that it rotates about an axis coincidentwith the axis of the said shaft. 3; spring d is ap plied "to the centralportion of the said dial to return the same, to normal position. Thesaid dial is provided on its under surface with a pivoted dog E, whichlatter has one portion (2 adapted to engage a notch or tooth c on thewheel C, and another portion a adapted to engage between two portions 6*carried on an arm e This arm 0 is rigid with and projects from one sideof the ratchet wheel which latter is mounted to turn loosely/upon thehub o The said ratchet wheel also has a lug f adapted to he engaged by{ly'SliOUltlBl f on the hack of the arm? of the dog. when the dial ispermitted to ,ret'urnto normal position, as will here inaftcr more fullyappear. The wheel C is provided with a cam portion c for restor- 9 ingthe portion c to engagement with the notch or tooth 0 upon therestoration of the mechanism to normal position. The said wheel C isalso provided with a projecting portion 1 adapted to he engaged by thedog G operated by the switch hook H. This dog G engages the portion 4*,when the receiver is on the hook, to lock the dial D against rotation.it dog I pivoted on the frame (5 provided with a tooth i to engage theteeth of the ratchet, wheel F, and with a projecting end portion 2"adapted to engage the cam portion 0 of the wheel tion, whereby the saidc adapted tog is disengaged from the ratchet wheel to allow the latterand the impulse wheel J to return in unison to normal position. Thisimpulse wheel is provided with teeth y, and is rigidly connected withthe hub 79 and with the wheel (I,

whereby they all move in unison. These teeth are adapted to engage thespring K when the dial is rotated forward, in the manner shown in Fig.7, the said teeth riding over the said spring, whereby the two normallyclosed springs y" and j ofthe line circuit are not opened. When the saidwheel is allowed to rotate back'to its normal position, then these teethslide over the spring K and thus open the two springs j and 7' in themanner shown in Fig. 8, It is the opening and closing OI these springs jand 7' that causes the transmission of the impulses in the line of thecalling subscriber,

whereby the automatic switches are operated at the central station. Itwill be understood that this make-and-break device is suitable for atwo-wire system-that is to say, a system in which there are no operatinggrounds at the subscribers stations.

"When the receiver is removed from the switch hook H the dog Gdisengages the portion 0 thereby unlocking the dial and placing the samein readiness to be rotated When the dial is rotated in the directionindicated by the arrow in Fig. 1, the wheel O is rotated by thehook-shaped portion e, and the ratchet wheel F is rotated by the portione, inasmuch as the latter engages the outer end of the arm 6 in the.manner explained. The dial is rotated forward in accordance with theparticular digit of the called number, and the dog 2' then, locks theratchet wheel F such position, holdipg the dial in the same position.The pivotal motion of the dog E, however, permits the dial to rotatebackward slightly, and this is sufiicient to throw the portion 0 out ofengagement with the tooth or'notch 0, by reason of the relative movementbetween the dial and the ratchet wheel F. In other words, this slightbackward movement of the dial causes the portion 6 to lift the portion eout of engagement with the wheel (J, the spring 0 supplying therequisite propelling power for this purpose. As soon as the wheel C isreleased, then the shaft B and the impulse wheel J rotate back to normalposition, operating the impulse springs and transmitting the impulsesduring the backward rotation. When the cam c engages the portion 2" ofthe dog I, then the ratchet wheel F is disengaged, and in this way thesaid ratchet wheel and dial D are automatically released and allowed toreturn to normal position. Obviously, though, the dial is locked againstmotion during the backward rotation of the impulse wheel J and duringthe transmission of the impulses. When the portion 6 engages the isremoved, as shown in Figs. at and 5. This i disengages the dog G fromthe portion 0 and thereby unlocks the dial in the manner explained. Whenthe receiver is replaced upon the hook, then the lug h is disengagedfrom the dog G, and the latter is returned to no: nal position by thespring 9, whereby the dial is normally locked againstrotation.

Thus it will be seen that I provide an im proved impulse-transmittingmechanism of such character that the dial, although of that type inwhich backward rotation thereof is incidental to the use of the same forcalling, cannot be forced or operated in such manner'as'to interferewith the proper transmission of the impulses. The dial is absolutelylocked against motion while the impulses are.being transmitted, which isimportant in systems of this character, and especially advantageous in atwo-wire systemthat is to say, a system in which the switches at thecentral station are controlled over the two sides of the line circuit inseries.

I have found that in a system of this kind it is particularly importantthat the impulses be transmitted properly and without any improperacceleration of the impulse wheel during its return to normal position.Furthcrmore, as explained, the dial is locked against motion while thereceiver is on the hook.

lVhat I claimas my-inyention is 1. A telephone exchangdsystem impulsetransmitter comprising a dial, an impulse wheel, means for returning thewheel to normal position, means for holding the dial locked in itsadvanced position, means @for releasing the dial when the wheel reachesits normal position, and means for returning the dial tomormal.

2. A telc'phone eschange system impulse transmitter comprising adial,'an impulse wheel, spring means for returning said dial and wheelto normal position, and means whereby the wheel returns first and thedial afterward.

3. A'telephone exchange system impulse transmitter comprising a dial, animpulse device, spring means for operating said device and returningsaid dial to normal position, means for releasing the device by slightbackward movement of the dia1, means for holdin the dial againstmovement While the device is sending the impulses, and means forreleasing the dial when the device is through sending the impulses.

e. In a telephone system, a suloscribefs calling dial, an impulse wheel,means for returning the wheel to normal position, means for holding thedial locked in'its advanced position, for releasing the dial when thewheel reaches its normal position, means for returning the dial tonormal, and means for normally locking the dial against rotation.

5. In a telephone system, a su-bscrihers calling dial, an impulse wheel,spring means for returning said dial and wheel to normal position, meanswhereby the wheel returns 7 first and the dial afterward, and means fornormally locking the dial a ainst rotation.

6. In a telephone system, a subscribers calling dial, an impulse device,spring means for operating the impulse de ice and returm ing the ial tonormal position, means for holding the dial against movement while thedevice is sending the impulses, and means for normally locking the dialagainst rotation.

7. In a telephone system, a suhscrihers calling dial, an impulse device,spring means for operating said device and returning said dial to normalposition, means for releasing the device by slight backward movement ofthe dial, means for holding the dial against movement while the deviceis sending the impulses, means for releasing the dial when the device isthrough sending the impulses, and means for normally locking the dialagainst rotation.

8. In a telephone system, a subscribers calling dial, spring means forreturning the dial to normal position, a ratchet device for holding thedial against inovement while the impulses are being transmitted, and

means for norn'ially locking thedial against rotation.

J. in a tvvo\vire telephone exchange systerm, a ailing dial therefor, animpulse wheel, means for returning the wheel to normal position, meansior holding the dial locked in Its advanced posltion, means tor -'rleasing the dial when the wheel reaches its normal position, means forreturning the dial to normal, and normally closed line sprlngs adaptedto be opened and closed to transmit the impulses.

11. In a two-Wire telephone exchange systcm, a calling dial therefor, animpulse vice, spring means for operating the impi Ase device andreturning the dial to normal position, means for holding the dialagainst movement. while the device is sending the impulses, and normallyclosed line springs adapted to he opened and closed to transmit theimpulses. I v

12. in a two-wire telephone exchange system, a calling dial therefor, animpulse device, spring means for operating said device and returningsaid dial to normal position,

4: i-.,,,: means lor releasing the device of, sllgnt backward movementof the dial, means for holding the dial against movement while thedevice is sending the impulse, scans for releasing the dial when thedevice is through sending the impulses, and normally closed line springsadapted to he opened and closed to transmit the impulses,

13. In a two-wire telephone exchange systern, a calling dial therefor,spring means for returning the dial to normal position, ratchet devicefor holding the dial against movement while the impulses are beingtransmitted, and normally closed line springs adapted to be opened andclosed to transmit the impulses.

It. In telephone system, a calling device having a reciprocatingoperating dial, a reciprocating impulse wheel, and means whereby saiddial and wheel operate indepen dently and sin'iultaneously:

15. In a telephone system, a calling device comprising are'ciprocatingdial, a reciprocating impulse wheel, means for operating said dial andwheel independently and simultaneously, and means for holding said dialagainst movement while said impulse .wheel is sending the impulses,

Signed by me at Chicago, Cook county, llliuois, this 10 day of June,1909.

l JOHN ERICKSON.

Witnesses EDWARD D. FALES, i-UITHUR J. RAY.

